Vacuum heat insulation material includes an outer covering material having a low gas or water permeation and a core material under vacuum state. In this reason, the vacuum heat insulation material is significantly excellent in heat shielding effect and has higher thermal insulation performance than existing heat insulation material such as polyurethane or Styrofoam. Thus, the vacuum heat insulation material is a high end material that currently has increasing demand.
The outer covering material for a typical vacuum heat insulation material is composed of a composite film with a plurality of layers laminated. The composite film basically comprises a protective layer, a barrier layer, and a sealing layer. The protective layer serves to ensure that the vacuum heat insulation material can primarily be protected from an external impact. The barrier layer serves to maintain an internal degree of vacuum and block ingress of an external gas or water vapor. The sealing layer serves to allow a close contact with the outer covering material and make the core material to keep a panel form.